As a result of regulatory mandate and good policy, the piping under sinks in public places is (at least in the United States) now routinely insulated to provide protection, particularly for wheelchair-bound individuals, against burns, scalding, abrasions, and other injury. While the patent art discloses numerous forms of protective covers for that purpose, particularly desirable systems are provided by Steven R. Trueb and Thomas W. Trueb (see for example U.S. Pat. Nos. 5,054,513, 5,303,730 and 5,360,031) and by John A. Helmsderfer (see for example U.S. Pat. Nos. 5,699,828 and 5,701,929), which patents are of common assignment herewith.
It is appreciated that two criteria (apart from essential protective functions) are particularly important in the provision of optimal pipe insulation of this kind: The components should be aesthetically attractive, with a smooth, graceful appearance, free from extraneous discontinuities and unduly exposed utilitarian mechanical features; and the design should be such that the time required for installation is minimized, as by facilitating or eliminating the need for measuring, marking, and cutting of the insulation pieces to achieve a proper fit on existing piping (the sections normally being made to excessive lengths, with that intent).
The above-mentioned U.S. Pat. No. 5,701,929 seeks to achieve the latter objective by incorporating structurally weakened areas (i.e., blind “perforations” or circumferential thin-wall areas) into a unitary body, which areas are located to permit manual separation for forming first and second cover pieces and to enable manual trimming of end portions during installation. In all instances the structurally weakened areas disclosed in the '929 patent appear to be comprised of elements extending inwardly from the exterior surface of the body. So too, U.S. Pat. No. 5,054,513 shows series of grooves formed into the outer surfaces of the tail piece and waste arm cover members, which grooves serve not only to receive fastening bands but also to designate locations for cutting. It is noted that the '730 and '031 patents describe a valve-insulating piece having a cover component that is secured to the main body by nips, or weak connecting elements, which are easily tearable to permit ready displacement of the cover component.
U.S. Pat. No. 5,699,828, also referred to above, addresses the need for measurement of the insulating pieces for proper fit, preliminary to cutting and trimming. The unitary body disclosed is formed with internal measurement indicia, extending longitudinally thereof, comprising a series of hash marks, spaced about ¼ inch apart, and associated consecutive numerical markings.